Wattage output switch question.

[Nose4Noise]

I've heard conflicting things around the best practice for using the wattage output switch on tube/valve head units (such as the one on the Marshall Origin 50). That is, switching between 0.5, 10, or 50 watts, for example...

I've been told that I should absolutely turn the amp off, let it sit for a minute or so, before selecting the desired output, then turning it back on again.

But equally I've been told that it doesn't matter, and you can switch away while the amp is in full flight.

What's the consensus?

 

[vivanchenko]

You can switch power when the amp is on. That's according to Marshall themselves. Don't remember where exactly I saw this. They just said don't do it too often (I assume don't play with it like with a Les Paul switch ) and you should be fine. For extra safety I also set the master volume to zero before I switch between power mods.

 

[SkyMonkey]

Hi @Nose4Noise and welcome to the MF

There is always a raging debate started by any mention of the 'Standby Switch'.
But here goes!

I have the DSL40CR which has a rocker switch to select between 40W/Standby/20W.
As you can see, the middle setting is Standby, flanked by the wattage modes.
That would force me to go into Standby (however briefly) to get from one wattage mode to the other.
Should I pause for a regulation amount of time in Standby before going to the alternate wattage mode.
Maybe.
But I don't.
Never had an issue with not using Standby on my DSL40CR, and I can't see why the amp would need a full Shut Off cooldown between modes.

There has never been a reported case of prematurely killing an amp by not using Standby (that I know of).

I am in the camp that believes Standby is actually unnecessary, and is only there because the 'general amp buying public' has become accustomed to having it, ever since Marshall first copied the design of a Fender amp which had Standby.
One theory is that the Standby switch protected fragile components used in the early days of guitar amp building.
Components are a lot more resilient these days.

The DSL 5W and 1W amps have no standby switch but still have wattage modes.
The DSL1 manual only says: "Use this switch to reduce power level from 1W down to 0.1W".
Old valve radios and TVs never had a Standby switch.
Just On/Off.

 

[dtier]

The Origin amps power level switch, power scales the screen supply. From my experience with using the screen supply as a standby function, I have observed a much softer transition of plate current than a traditional standby switch, (no current spikes). I haven't observed the Origin plate current while switching power modes yet but I'll bet it's a quite smooth transition. The Origin amps don't have a standby function on the power level switch.

 

[Nose4Noise]

So this in my mind prompts to the confusion. The absence of a standby switch (in the Origin 50) could lead you to two separate opposing conclusions.
A) There's no standby switch, so you need to turn it off before power switching. The fact that other amps have this function, tells us that turning it off first is the probably the safest thing to do.
B) There's no standby switch, so Marshall is implicitly signalling that not only is a standby switch not necessary, but also by extension turning the amp off before switching is also unnecessary.

 

[SkyMonkey]

So this in my mind prompts to the confusion. The absence of a standby switch (in the Origin 50) could lead you to two separate opposing conclusions.
A) There's no standby switch, so you need to turn it off before power switching. The fact that other amps have this function, tells us that turning it off first is the probably the safest thing to do.
B) There's no standby switch, so Marshall is implicitly signalling that not only is a standby switch not necessary, but also by extension turning the amp off before switching is also unnecessary.

Hence all the arguments a Standby switch can raise in a forum debate.

Standby vs shutting down amp. Possible dumb ?

On my days off, I get 30-60 minute practice sessions in periodically throughout the day. When I know I’ll be back in 30ish minutes. I usually leave amp in standby. If it’s going to be long I usually shut everything down. Any thoughts? Am I overthinking this lol! But I assume there is...

www.marshallforum.com

 

[PelliX]

So this in my mind prompts to the confusion. The absence of a standby switch (in the Origin 50) could lead you to two separate opposing conclusions.

Well, the absence is more a design choice. They wanted two switches because "that's what all them Marshalls have". One has to be power, that leaves... yeah.

A) There's no standby switch, so you need to turn it off before power switching. The fact that other amps have this function, tells us that turning it off first is the probably the safest thing to do.

No. Turning it off would actually stress the valves a little more, probably due to the cool down and ramp up of the temperature. Every "cycle" will have some effect, albeit next to nothing in most cases.

B) There's no standby switch, so Marshall is implicitly signalling that not only is a standby switch not necessary, but also by extension turning the amp off before switching is also unnecessary.

A standby switch is indeed not necessary for the amp itself. It's handy if you want to swap cabs, etc - but for the amp's operation it adds no value.

I have the DSL40CR which has a rocker switch to select between 40W/Standby/20W.
As you can see, the middle setting is Standby, flanked by the wattage modes.
That would force me to go into Standby (however briefly) to get from one wattage mode to the other.
Should I pause for a regulation amount of time in Standby before going to the alternate wattage mode.
Maybe.
But I don't.
Never had an issue with not using Standby on my DSL40CR, and I can't see why the amp would need a full Shut Off cooldown between modes.

In the case of the DSL it kills the B+ when you go to standby and switches it back on at a given voltage depending on the position you select (High/Low). That's quite different to actually powering the amp off where the heaters would shut down, too. When you switch from High to Low quickly, you'll hear a thump generally - that's the high voltage caps discharging and charging to the new voltage level. I feel that it's probably less harsh on the parts to give it a few seconds to bleed/drain but I agree that it won't cause much harm when ignored.

 

[Edgar Frog]

I contacted Marshall about the switch many years ago. They said the switch can normally be used while the amp is on, just don't rapidly or repeatedly switch between settings. I take that as giving it a second or 2 between each setting. It's best IMHO just to pick what you want to use before firing it up. Once you are accustomed to it that should be easy to figure out for your needs at any given time. Since I only use preamp gain and run the power section clean I always have my Origin 20H on full power.